Lack of Pathologic Q Waves: A Specific Marker of Viability in Myocardial Hibernation

BACKGROUND: The present study evaluates the lack of Q waves on the electrocardiogram (ECG) in the prediction of myocardial viability compared with dobutamine stress echocardiography (DSE) and rest‐redistribution thallium‐201 (Tl‐201) scintigraphy. HYPOTHESIS: The lack of pathologic Q waves (NoQ) may be a readily available and specific marker for the presence of viability. METHODS: Sixty four patients with stable coronary artery disease (CAD) and ventricular dysfunction underwent rest ECG, DSE, and Tl‐201 scintigraphy before revascularization, and a repeat rest 2‐Dimensional (2‐D) echocardiogram more than 3 mo later. RESULTS: Total viability at baseline (% of total segments) was higher in the NoQ group by Tl‐201 scintigraphy (87 ± 19% versus 70 ± 20%, p = 0.008) and by DSE (81 ± 20% versus 65 ± 24%, p = 0.013). As expected, the sensitivity of NoQ waves was low in predicting recovery of function (23%), and inferior to Tl‐201 (82%) and DSE (84%) (p<0.08). However, specificity of NoQ waves for predicting recovery of global function was high (72%); higher than Tl‐201 (50%) and DSE (45%). Positive predictive values were comparable among all modalities. Results were similar if the data were analyzed regionally for viability. CONCLUSION: Lack of pathologic Q waves is a specific and readily available marker of myocardial viability in patients with chronic CAD, which should alert the clinician for myocardial hibernation. Copyright © 2008 Wiley Periodicals, Inc.